Extra-Broad Band Orange-Emitting Ce3+-Doped Y3Si5N9O Phosphor for Solid-State Lighting: Electronic, Crystal Structures and Luminescence Properties

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• 作者：Qiang-Qiang Zhu ; Le Wang ; Naoto Hirosaki ; Lu Yuan Hao ; Xin Xu ; Rong-Jun Xie
• 刊名：Chemistry of Materials
• 出版年：2016
• 出版时间：July 12, 2016
• 年：2016
• 卷：28
• 期：13
• 页码：4829-4839
• 全文大小：781K
• 年卷期：0
• ISSN：1520-5002

文摘

Luminescent materials play an important role in making solid state white light-emitting diodes (w-LEDs) more affordable home lighting applications. To realize the next generation of solid-state w-LEDs with high color-rendering index (CRI), the discovery of broad band and long emission wavelength luminescent materials is an urgent mission. Regarding this, the oxonitridosilicate Y₃Si₅N₉O with a high nitrogen concentration should be a suitable host material to achieve those promising luminescent properties. In this work, a phase-pure Ce³⁺-doped Y₃Si₅N₉O was successfully synthesized through the carbothermal reduction and nitridation method. Y₃Si₅N₉O:Ce³⁺ shows an emission maximum at 620 nm and an extremely broad emission band with a full-width at half-maximum (fwhm) of 178 nm. The electronic and crystal structure calculations indicate an indirect band gap of 2.6 eV (experimental value: 4.0 eV), and identify two Ce³⁺ sites with different local environments that determine the luminescence properties. The orange-emitting phosphor has the absorption, internal and external quantum efficiencies of 89.5, 17.2, and 15.6% under 450 nm excitation, respectively. The valence state of Ce, cathodoluminescence, decay time, and thermal quenching of the phosphor were also investigated to understand the structure–property relationships.